Portable Fishfinder - Custom Build

I have been toying with the idea of adding a fishfinder to my drift boat. Since it is a small boat with no 12v system and no easy way to mount the transducer, I thought along the lines of a small portable system. What I was finding was not all that great. Some were too small others had no features or cheap mounts. The nicer units I did find had poor battery life. So I decided to build my own.

This proto-type uses a Garmin 160C fishfinder, 10ah power source and should give me about a 10-15 hour operating time. I'll be testing it out as well as the portable rig I built over the next few months I hope to posts some positive experiences. Time will tell.

Update 3-12-10:
Works like a charm. I'm getting 15 - 18 hours run time on the 10ah battery.
I replaced the power switch on the box to an LED version and it creates no heat now and hardly any drain on the battery. The sonar unit itself seems very nice. Clear picture, very sensitive and does a god job finding the fish, even the ones holding below overhangs or dense structure.
The suction cup transducer mount I ordered from Garmin works great. No worries about it coming loose while on the move. Overall I am very happy with how it turned out.